Railway signaling system.



Patented Dec. 23, I902.

(Application filed Feb. 26, 1902.)"

(No Model.)

ATTORNEY WlTNESSES:

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YVILLIAM LOOKE, OF TROY, NEW YORK, ASSIGNOR TO PNEUMATIC SIGNAL COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NE /V YORK.

RAILWAY SIGNALING SYSTEM.

SPECIFEOATION forming part of Letters Patent No. 716,562, dated December 23, 1902.

Application filed February 26, 1902. Serial No. 95,695. (No model.)

To aZZ whom it 77l/(t 7./ concern:

Be it known that 1, WILLIAM LooKE, a citizen of the United States, residing at Troy, in the county of Rensselaer and State of New York, have invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to railway signaling systems.

Oneof the objects of my invention is to dispense with line-wires by the utilization of the rails of the track as the only conductors from point to point along the railway-line.

Another object of my invention is to provide for home and distant indications with such all-rail circuits and without the use of polarized relays.

Other objects of my invention are preventing the giving of a safety-signal by the derangement, impairment, or breakage of any parts of the system and economy and reliability of action.

According to my invention an electric current is conveyed to the track in proximity to the front end of a block or section, and an electric current is also conveyed to the track in proximity to the rear end of the block or section and may be so conveyed from one or more sources of electric energy, as a dynamoelectric machine or separate batteries or storage batteries charged by a dynamoelectricmachine,and means controlled from a point in ad- Vance of the block or section are provided for reversing the direction of the flow of current at one of such connections, and two non-polar rear relays are provided, one included in the rear electric-current connection and the other in multiple therewith, so that when the current introduced at these two points flows in the same direction both of the rear relays will be operatively energized, and when the current introduced at these two points flows in opposite directions only one of the rear relays will be operatively energized. The rear relays control suitable means for controlling the trafiic on the railway-line, such as visual signals, and the two rear relays are utilized in effecting home and distant indications.

I will now describe the construction and arrangement of circuits and apparatus illustrated in the accompanying drawing and will thereafter point out my invention in claims.

The accompanying drawing illustrates diagrammatically several blocks of railway provided with home and distant signals. The signals are shown as semaphores of ordinary construction, three home signals 1, 2, and 3 and three distant signals 4, 5, and 6 being shown. The signal-operating mechanism is not shown, the wires thereto being diagrammatically shown as running to the semaphores.

The several blocks of the trackA B C D are insulated from each other in the usual manner and the rails of the diiferent blocks are connected in similar circuits. The complete circuits of two blocks 13 and O and portions of the circuits of blocks A and D are shown, and the circuits and signals are shown in the condition which they would assume with a train in the front block D, as indicated at 7. For this condition of traffic the home signal 3 and the distant signal 6 of the front block D are at danger, and the distant signal 5 of the block 0 in the rear of block D is at danger, and all other signals are in the normal safety position. The circuits of the block B (the second block in rear of that occupied by the train) are in the normal condition, and I will therefore first describe the circuits of this block B.

Two track-batteries are provided, one at each end of the block, the battery 8 at the front end of the block, this front-track battery 8 being shown as of two cells, and the battery 9 at the rear end of the block, this rear-track battery 9 being shown as of one cell, and two rear or track relays, both nonpolar, the relay 10 of relatively low resistance and the relay ll of relatively high resistance. rear relay 10 controls a number of contacts through a number of armature-fingers, all of which move together and with the armature, and the high-resistance rear relay 11 controls only one front contact through an armaturefinger. The illustration is diagrammatic and conventional, the armatures not being shown.

The armature of the low-resistance Normally the current from the front-track battery 8 flows through wire 12, armaturefinger 13, front contact 14, wire 15, to the rail shown at the top of the drawing and which I shall designate as the upper rail, through the upper rail to the rear end of the block B, and through wire 16, coils of low-resistance track-relay 10, and by wire 17 to the lower rail, through the lower rail to the front end of the block, and by wire 18, front contact 19, armature-finger 20, and wire 21 back to battery. The current from this front-track battery also has a path in multiple with the coils of the low-resistance rear relay from wire 16, through wire 23, one coil of the highresistance rear relay 11, wire 24, armaturefinger 25, and front contact 26 of the lowresistance relay 10, wire 27, rear-track battery 9, in the direction of the polarity thereof, the other coil of the high resistance rear relay 11, and wire 22 to wire 17. The current of the front-track battery 8 will to some extent aid the rear-track battery 9 in energizing the coils of the low-resistance rear relay 10. The current from this rear-track battery 9 normally flows through one coil of the high-resistance rear relay 11, and thence through wire 22 to wire 17, thence through wire 17 tolower rail, and through the connections above described of the front-track battery, and the front-track battery itself in the direction of the polarity thereof, leaving such circuit at the wire 16 by wire 23, through the other coil of the high-resistance rear relay 11, wire 24, armature-finger 25, front contact 26, and wire 27 back to battery. Under this normal condition of the circuits both rear relays will be energized and their armatures held attracted and both the home signal 1 and the distant signal 4 maintained in their normal clear position.

The signal-circuit for the home signal 1 is as follows: from main battery 28 by wire 29 to the home signal-operating mechanism, returning by wire 30, armature-finger 31, and front contact 32 of low-resistance rear relay 10, and wire 33 back to battery. Thus the low-resistance rear relay 10 controls the home signal, as the retraction of the armature of this relay will open the signal-circuit at the contact 26.

The signal-circuit for the distant signal 4 is as follows: from main battery 28, through wire 29, through the operating mechanism of the home signal 1 in the usual manner, so that the circuit cannot be closed unless the home signal is at safety, and by wire 34 to the dist-ant-signal-operating mechanism, and returning by Wire 35, front contact 36, and armature-finger 37 of the low-resistance rear relay 10, wire 38, front contact 39, and armature-finger 40 of high-resistance rear relay 11, and wire 41 back to battery. Thus the low-resistance rear relay 10 and the high-resistance rear relay 11 both control the distant signal, as they must both attract their armatures to maintain the distant signal at safety, and the retraction of the armature of the low-resistance rear relay 10 will open the signal-circuit of the distant signal at the contact 36, and the retraction of the armature of the high-resistance rear relay 11 will open the signal-circuit of the distant signal at the contact 39, and any other condition than that of safety of the home signal will prevent a safety indication by the distant signal.

I will now describe thecondition of the circuits with a train in the block, referring to the block D, which illustrates such a condition. The presence of the train in the block shunts the circuit of the front-track battery, (not shown,) and thereby cuts off the energizing-current of the low-resistance rear relay 42 of the block D, causing the armature of this relay to be retracted and opening all front contacts thereof, thereby opening the circuit of the rear-track battery 43 of the block D. tery 43 thus opened was as follows: from battery 43 through one coil of the high-resistance rear relay 44, wires 45 46, lower-rail connections (not shown) corresponding to those already described at the front end of the block, including the front-track battery in the direction of the polarity thereof, upper rail, Wires 47 48, the other coil of the highresistance rear relay 44, wire 49, armaturefinger 50, and front contact 51. of the low-resistance rear relay 42, and wire 52 back to the battery. This circuit is now open at the contact 51. It will be noted that the normal flow of current from the rear-track battery 43 is not through the low-resistance rear relay 42, as it could only flow therethroughin opposition to the current of the front-track battery and will therefore take the easier path above described in the same direction as the current of the front-track battery to and through the rails, and, further, that when the current of the front-track battery is shu nted by the train, and thereby the opposing current through the coils of the low-resistance rear relay 42 is removed, the path through the rails for the current of the rear track battery 43 becomes a low-resistance multiple or shunt of the path for this current through the coils of the lowresistance rear relay 42, and thus the train in the block shunts both the front and the rear track batteries as to the low-resistance rear relay 42. The presence of a train in a block therefore causes the armature of the low-resistance rear relay to be quickly retracted, thereby opening the circuit of the rear-track battery and deenergizing the high-resistance rear relay. The signal circuit for the home signal 3 thus opened was as follows: from main battery 53 by wire 54 to the home-signal-operating mechanism and returning by wire 55, armature-finger 56, and front contact 57 of lowresistance rear relay 42, and wire 58 back to battery. This circuit is open at the contact 57. The signal-circuit for the distant signal The circuit of the rear-track bat- 6 thus opened was as follows: from main battery 53 by wires 54 to the operating mechanism of the home signal 3, so as to be open when the home signal is in any other than the safety position, and through wire 59 to the distant-signal-operating mechanism and returning by wire 60, front contact 61, and armature-finger 62 of low-resistance rear relay 42, wire 63, front contact 64, and armaturefinger 65 of high-resistance rear relay 44, and wire 66 back to battery. This circuit is open both at the contact 61 and the contact 64 and is also opened by the movement of the home signal 3 to danger. The retraction of the armature of the low-resistance rear relay of the block D, resulting from the presence of a train in the block D, alsoeffects a reversal of the normal connection of the front-track battery 67 of the block 0 in rear of the block D by the opening of front contacts and the closing of the back contacts of the low-resistance rear relay 42 and the current for this fronttrack battery now flows as follows: from battery 67 by Wire 68, armature-finger 69, and back contact 70 of lowmesistance rear relay 42 of block D, wire 71, lower rail of block 0, wire 72, coils of low-resistance rear relay 73 of block G, Wire 74, upper rail of block 0, wire 75, back contact 76, and armature-finger 77 of low-resistance rear relay 42 of block D, and wire 78 back to battery. This circuit energizes the low-resistance rear relay 73 and causes it to attract its armature, closing its front points, and thereby restoring the home signal 2 of the block C to the normal safety position. The signal-circuit for the home signal 2 of the block 0 is as follows: from main battery 87 through wire 88, operating mechanism of home signal 2, wire 89, armature-finger 90, and front contact 91 of low-resistance rear relay 73 and wire 92 back to battery. The closing of the front points of the low-resistance rear relay 73 also closes the circuit of the rear-track battery 81, as follows: from battery 81 through one coil of high-resistance rear relay 80, wires 79 72, lower rail, wire 71, back contact 70, and armature-finger 69 of low-resistance rear relay 42 of block D, wire 68, front-track battery 67 in opposition to the polarity thereof, wire 78, armature-finger 77, and back contact 76 of low-resistance rear relay of block D, wire 75, upper rail, wires 74 86, other coil of high-resistance rear relay 80 of block 0, wire 85, armature-finger 84, and front contact 83 of low-resistance rear relay 73 of block 0, and wire 82 back to battery. Although this circuit is now closed at the contact 83, the current which tends to flow therethrough from the rear-track battery 81 is in opposition to the current flowing therethrough from the front-track battery 67, and in consequence thereof the rear-track battery will be overcome or its current so weakened that it will not cause the high-resistance rear relay S0 to attract its armature. On the other hand, the current of the front-track battery 67 could not both overcome the rear-track battery 81 and sufficiently energize the high-resistance rear relay 80 to cause attraction of its armature, for the reason that the coils of the lowresistance rear relay 73 are in multiple with the coils of the high-resistance rear relay 80 through the circuit first described as energizing the low-resistance rear relay 73, and having in one branch the resistance of the coils of a high-resistance relay and the oppposition of a battery, and in the other branch only the resistance of the coils of a low-resistance relay could not in any event operatively energize the high-resistance rear relay 80. The signal-circuit of the distant signal 5 of the block 0 will therefore remain open and the distant signal 5 will remain at danger. This signal-circuit may be traced as follows: from main battery 87 through wire 88, through the operating mechanism of the home signal 2, so as to be open when the home signal is in any other than the safety position, through the wire 93,operating mechanism of the distant signal 5, wire 94, front contact and armature-finger 96 of low-resistance rear relay 73, wire 97, front contact 98, and armature-finger 99 of high-resistance rear relay 80, and wire 100 back to battery, and this circuit is held open at the contact 98 so long as the front-track battery 67 and the rear-track,

battery 81 are opposed, as above described, and is held open until the home signal 2 has returned to safety. When the train passes out of the block D, its shunting action will be removed from the track-circuits ofthe block D and a condition of circuits and signals, such asjust described relative to the circuits and signals of the block 0, will be set up in the block D-1l.e.', the current of the fronttrack battery of the block D will be reversed and thereby the low-resistance rear relay 42 of the block D will be caused to attract its armature and the high-resistance rear relay 44 of the block D will be unable to attract its armature. The closing of the front points of the low-resistance rear relay 42 of the block D will restore the normal flow of current of the front-track battery 67 of. the block 0, and the currents of the front and rear track batterieswill then flow in the same direction through the common parts of their circuits, and the normal condition of the circuits and apparatus heretofore described relative to the block B will be restored in the block 0. Any failure of battery-power or breakage of lines will cause a danger indication. If, for example, a reartrack battery, as 9, should fail, the current from the front-track battery 8 through the rails will not be strong enough to hold up the armature of the high-resistance rear relay 11, and therefore the distant signal will remain at danger until the rear-track battery is renewed; or should a wire from the track become broken or one of the rails become broken the current from the rear-track battery, as 9, will be unable to sufficiently energize the low-resistance rear relay 10 to &

hold up or attract its armature, for the rea son that the resistance of the high-resistance rear relay 11 so reduces the current output of the rear-track battery 9 that this battery alone is unable to supply sufficient current to actuate the low-resistance rear relay 10. Again, on the failure of a front-track battery, as 8, the low-resistance rear relay 10 will be unable to hold up or attract its armature, and the circuit of the rear-track battery 9 will be opened at the front contact 26, so that both rear relays will be inoperative until the front track battery is renewed. Further, the signal-circuit for the distant signal must be closed at front contacts of both rear relays, as the contacts 36 and 39, to maintain the distant signal at danger, and the distant-signal circuit is through the homesignal apparatus in the well-known manner, as by wires 29 34, so that when the home signal goes to danger it opens the signal-circuit of the distant signal.

From the above description it will be evident that the armature-fingers connected to the front-track batteries, as the armaturefingers 13 and 20 of the low-resistance rear relay 73 of the block 0, in connection with their contacts, as the front contact 14, back and front contact 19, and back contact 101 of such armature-fingers 13 and 20, constitute polechangers for the front-track batteries, as the battery 8, their function being to reverse the direction of the flow of current from the fronttrack batteries to the rails.

It is evident that various modifications may be made in the construction and arrangement of the circuits and apparatus illustrated in the drawings and above particularly described within the spirit and scope of my invention.

What I claim, and desire to secure by Letters Patent, is-

1. The combination with the track of a block or section, of one or more sources of electric energy connected to the track in proximity to the front end of the block or section and connected to the track in proximity to the rear end of the block or section, a pole-changer interposed in such front-track connection, means for controlling such pole-changer from a point in advance of the block or section, two non-polar relays connected to the track in proximity to the rear end of the block or section, one of such relays being included in the rear-track connection of the source or sources of electric energy and the other relay connected in multiple with the first-mentioned relay, and traffic-controlling means controlled by such relays.

2. The combination of a plurality of tracksections each having one or more sources of electric energy connected to the track in proximity to the front end and in proximity to the rear end thereof, a pole-changer interposed in such front-track connection, two non-polar relays connected to the track in proximity to the rear end of the section, one of such relays being included in the rear-track connection of the source or sources of electric energy and the other relay connected in multiple with the first-mentioned relay, the last-mentioned relay of each section controlling the polechanger of the section in rear, and traffic-controlling means controlled by such relays.

3. The combination with the track of a block or section, of a source of electric energy connected to the track in proximity to the front end of the block or section, a pole-changer interposed in such connection, means for controlling such pole-changer from a point in advance of the block or section, a non-polar relay connected to the track in proximity to the rear end of the block or section, a source of electric energy and another non-polar relay also connected to the track in proximity to the rear end of the block or section, and traificcontrolling means controlled by such relays.

4c. The combination of a plurality of tracksections each having a source of electric energy connected to the track in proximity to the front end thereof, a pole-changer interposed in such connection and a non-polar relay connected to the track in proximity to the rear end thereof, such non-polar relay controlling the pole changer of the section in rear, each track-section also having a source of electric energy and another non-polar relay connected to the track in proximity to the rear end thereof, and traffic-controlling means controlled by such relays.

5. The combination of the track of a block or section, a front-track battery, two nonpolar rear-track relays connected in multiple, a rear-track battery interposed in one of such multiple connections, means for connecting such batteries in the same direction to operate both of such relays and in opposition to operate one only of such relays, and trafficcontrolling means controlled by such relays.

6. The combination of a plurality of tracksections each having a front-track battery, two non-polar rear-track relays connected in multiple, a rear-track battery interposed in one of such multiple connections, a polechanger for the front-track battery controlled by a rear-track relay of the section in advance, and traffic controlling means controlled by such relays.

7. The combination of the track of a block or section, a source of electric energy connected to the track in proximity to the front end of the block or section, a pole-changer interposed in such connection, means for con trolling such pole-changer from a point in advance of the block or section, a low-resistance relay directly connected to the track in proximity to the rear end of the block or section, a high-resistance relay connected to the track in proximity to the rear end of the block or section in multiple with the low-resistance relay, a source of electric energy interposed in the multiple connection of the high-resistance relay, and traflic-controlling means controlled by such relays.

8. The combination of a plurality of tracksections, each having a source of electric energy connected to the track in proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such lowresistance relay controlling the pole-changer of the section in rear, and each track-section having a high-resistance relay connected to the track in proximity to the rear end of the section in multiple with the low-resistance relay and a source of electric energy interposed in the multiple connection of the high-resistance relay, and traffic-controlling means controlled by such relays.

9. The combination of the track of a block or section, a source of electric energy connected to the track in proximity to the front end of the block or section, a pole-changer interposed in such connection, means for controlling such pole-changer from a point in ad- Vance of the block or section, a non-polar relay connected to the track in proximity to the rear end of the block or section, a source of electric energy and another non-polar relay also connected to the track in proximity to the rear end of the block or section in multiple with the first-mentioned relay, a circuit make and break device in such multiple connection and controlled by the first-mentioned relay, and traffic-controlling means controlled by such relays.

10. The combination of a plurality of tracksections each having a source of electric energy connected to the track in proximity to the front end thereof, a pole-changer interposed in such connection and a non-polar relay connected to the track in proximity to the rear end thereof, such non-polar relay controlling the pole-changer of the section in rear, each track-section also havinga source of electric energy and another non-polar relay connected to the track in proximity to the rear end thereof in multiple with such first-mentioned relay and a circuit make and break device in such multiple connection controlled by the first-mentioned relay, and traffic-controlling means controlled by such relays.

11. The combination of the track of a block or section, a source of electric energy connected to the track in proximity to the front end of thelblock or section, a pole-changer interposed in such connection, means for controlling such pole-changer from a point in advance of the block or section, a low-resistance relay directly connected to the track in proximity to the rear end of the block or section, a high-resistance relay connected to the track in proximity to rear end of the block or section in multiple With the low-resistance relay, a source of electric energy and a circuit make and break device interposed in the multiple connection of the high-resistance relay, the

circuit make and break device being con-' trolled by the low-resistance relay, and trafficcontrolling means controlled by such relays.

12. The combination of a plurality of tracksections, each having a source of electric energy connected to the track in proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such lowresistance relay controlling the pole-changer of the section in rear, and each track-section having a high-resistance relay connected to the track in proximity to the rear end of the section in multiple with the low-resistance relay and a source of electric energy and a circuit make and break device interposed in the multiple connection of the high-resistance relay, the circuit make and break device being controlled by the low-resistance relay, and traffic-controlling means controlled by such relays.

13. The combination of the track of a block or section, a source of electric energy connected to the track in proximity to the front end of the block or section, a pole-changer interposed in such connection, means for controlling such pole-changer from a point in advance of the block or section, a low-resistance relay directly connected to the track in proximity to the rear end of the block or section, a high-resistance relay connected to the track in proximity to the rear end of the block or section in multiple with the low-resistance relay, a source of electric energy interposed in the multiple connection of the high-resistance relay between the coils thereof, a circuit make and break device in such multiple connection of the high-resistance relay and controlled by the loW-resistance relay,and trafliccontrolling means controlled by such relays.

14. The combination of a plurality of tracksections, each having a source of electric energy connected to the trackin proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such low-resistance relay controllingthe pole-changer of the section in rear, and each track-section having ahigh-resistance relay connected to the track in proximity to the rear end of the section in multiple with the low resistance relay, a source of electric energy interposed in the multiple connection of the high-resistance relay between the coils thereof, and a circuit make and break device in such multiple connection of the high-resistance relay and controlled by the low-resistance relay, and trafficcontrolling means controlled by such relays.

15. In a railway signaling system, the combination of the track of a signaling-block, one or more sources of electric energy connected to the track in proximity to the front end of the block and connected to the track in proximity to the rear end of the block, a polechanger interposed in such front-track connection, means for controlling such polechanger from a point in advance of the block, two non-polar relays connected to the track in proximity to the rear end of the block, one of such relays being included in the rear-track connection of the source or sources of electric energy and the other relay connected in multiple with the first -mentioned relay, a home signal controlled by the other relay and a distant signal controlled by the first-mentioned relay.

16. In a railway signaling system, the combination of the track of a plurality of signaling-blocks, each of such blocks having one or more sources of electric energy connected to the track in proximity to the front end and in proximity to the rear end thereof, a polechanger interposed in such front-track connection, two non-polar relays connected to the track in proximity to the rear end of the block, one of such relays being included in the rear-track connection of the source or sources of electric energy and the other relay connected in multiple with the firstmentioned relay, the last-mentioned relay of each block controlling the pole changer of the block in rear, a home signal for each block controlled by the last-mentioned relay thereof and a distant signal for each block controlled by the first-mentioned relay thereof.

17. In a railway signaling system, the combination of the track of a signaling-block, a source of electric energy connected to the track in proximity to the front end of the block, a pole-changer interposed in such connection, means for controlling such polechanger from a point in advance of the block, a non-polar relay connected to the track in proximity to the rear end of the block, a source of electric energy and another nonpolar relay also connected to the track in. proximity to the rearend of the block, a home signal controlled by thefirst-mentioned relay, and a distant signal controlled by the lastinentioned relay.

18. In a railway signaling system, the combination of the track of a plurality of signalingblocks, each of such blocks having a source of electric energy connected to the track in proximity to the front end thereof, a pole-changer interposed in such connection and a non-polar relay connected to the track in proximity to the rear end thereof, such nonpolar relay controlling the pole-changer of the block in rear, each block also having a source of electric energy and another non-polar relay connected to rear end thereof, a home signal for each block controlled by the first-mentioned relay thereof and a distant signal for each block controlled by the last-mentioned relay thereof.

19. In a railway signaling system, the combination of the track of a signaling-block, a front-track battery, two non-polar rear-track relays connected in multiple, a rear-track battery interposed in one of such multiple connections, means for connecting such batteries in the same direction to operate both of such relays and in opposite directions to operate only the relay in the multiple connection not the track in proximity to the including the rear-track battery, a home signal controlled by the relay in the multiple connection not including the rear-track battery, and a distant signal controlled by the other relay.

20. In a railway signaling system, the combination of the track of a plurality of signaling-blocks, each of such blocks havingafronttrackbattery, two non-polar rear-track relays connected in multiple, a' rear-track battery interposed in one of such multiple connections, a pole-changer for the front-track battery controlled by the rear-track relay of the block in advance in the multiple connection not including the rear-track battery, a home signal for each block controlled by the relay thereof in the multiple connection not including the rear-track battery, and a distant signal for each block controlled by the other relay thereof.

21. In a railway signaling system, the combination of the track of a signaling-block, a source of electric energy connected to the track in proximity to the front end of the block, a pole-changerinterposed in such connection, means for controlling such polechanger from a point in advance of the block, a low-resistance relay directly connected to the track in proximity to the rear end of the block, a high-resistance relay connected to the track in proximity to the rear end of the block in multiple with the low-resistance relay, a source of electric energy interposed in the multiple connection of the high-resistance relay, a home signal controlled by the low-resistance relay and a distant signal controlled by the high-resistance relay.

22. In a railway signaling system", the combination of the track of a plurality of signaling-blocks, each of such blocks having a source of electric energy connected to the track in proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such low-resistance relay controlling the pole-changer of the block in rear, each block having a high-resistance relay connected to the track in proximity to the rear end thereof in multiple with the lowresistance relay and a source of electric energy thereof interposed-in the multiple connection of the high-resistance relay, a home signal controlled by the low-resistance relay and a distant signal controlled by the highresistance relay.

23. In a railway signaling system, the combination of the track of a signaling-block, a source of electric energy connected to the track in proximity to the front end of the block, a pole-changer interposed in such connection, means for controlling such polechanger from a point in advance of the block, a non-polar relay connected to the track in proximity to the rearend of the block, a source of electric energy and another non-polar relay also connected to the track in proximity to the rear end of the block in multiple with the first-mentioned relay, a circuit make and break device in such multiple connection and controlled by the first mentioned relay, a home signal controlled by the first-mentioned relay and a distant signal controlled by the other relay.

24. In a railway signaling system, the combination of the track of a plurality of signaling-blocks, each of such blocks having a source of electric energy connected to the track in proximity to the front end thereof, a pole-changer interposed in such connection and a non-polar relay connected to the track in proximity to the rear end thereof, such non-polar relay controlling the pole-changer of the block in rear, each block also having a source of electric energy and another nonpolar relay connected to the track in proximity to the rear end thereof in multiple with such first-mentioned relay and a circuit make and break device in such multiple connection controlled bythe first-mentioned relay,a home signal for each block controlled by the firstmentioned relay thereof and a distant signal for each block controlled by the other relay thereof.

25. In a railway signaling system, the combination of the track of a signaling-block, a source of electric energy connected to the track in proximity to the front end of the block, a pole-changer interposed in such connection, means forcontrolling such polechanger from a point in advance of the block, a low-resistance relay directly connected to the track in proximity to the rear end of the block, a high-resistance relay connected to the track in proximity to the rear end of the block in multiple with the low-resistance relay, a source of electric energy and a circuit make and break device interposed in the multiple connection of the high-resistance relay, the circuit make and break device being controlled by the low-resistance relay, a home signal controlled by the low-resistance relay and a distant signal controlled by the highresistance relay.

26. In a railway signaling system, the combination of the track of a plurality of signalingblocks, each of such blocks having a source of electric energy connected to the track in proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such low-resistance relay controlling the pole-changer of the block in rear, and each block having a high-resistance relay connected to the track in proximity to the rear end of the block in multiple with the low-resistance relay and a source of electric energy and a circuit make and break device interposed in the multiple connection of the high-resistance relay, the circuit make and break device being controlled by the low-resistance relay, a home signal for each block controlled by the low-resistance relay thereof and a distant signal for each block controlled by the high-resistance relay thereof.

27. In a railway signaling system, the combination of the track of a signaling-block, a source of electric energy connected to the track in proximity to the front end of the block, a pole-changer interposed in such connection, means for controlling such polechanger from a point in advance of the block, a low-resistance relay directly connected to the track in proximity to the rear end of the block, a high-resistance relay connected to the track in proximity to the rear end of the block in multiple with the low-resistance relay, a source of electric energy interposed in the multiple connection of the high-resistance relay between the coils thereof, a circuit make and break device in such multiple connection of the high-resistance relay and controlled by the low-resistance relay, a home signal controlled by the low-resistance relay and a distant signal controlled by the high-resistance relay.

28. In a railway signaling system, the combination of the track of a plurality of signaling-blocks, each of such blocks having a source of electric energy connected to the track in proximity to the front end thereof and a pole-changer interposed in such connection and a low-resistance relay directly connected to the track in proximity to the rear end thereof, such low-resistance relay controlling the pole-changer of the block in rear, and each block having a high-resistance relay connected to the track in proximity to the rear end of the block in multiple with the low-resistance relay, a source of electric en- WVILLIAM LOOKE.

Witnesses:

HENRY D. WILLIAMS, HERBERT H. GIBBs. 

